1 //===- X86RegisterInfo.cpp - X86 Register Information -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the X86 implementation of the TargetRegisterInfo class.
11 // This file is responsible for the frame pointer elimination optimization
14 //===----------------------------------------------------------------------===//
17 #include "X86RegisterInfo.h"
18 #include "X86InstrBuilder.h"
19 #include "X86MachineFunctionInfo.h"
20 #include "X86Subtarget.h"
21 #include "X86TargetMachine.h"
22 #include "llvm/Constants.h"
23 #include "llvm/Function.h"
24 #include "llvm/Type.h"
25 #include "llvm/CodeGen/ValueTypes.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineFunctionPass.h"
29 #include "llvm/CodeGen/MachineFrameInfo.h"
30 #include "llvm/CodeGen/MachineLocation.h"
31 #include "llvm/CodeGen/MachineModuleInfo.h"
32 #include "llvm/CodeGen/MachineRegisterInfo.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/Target/TargetFrameInfo.h"
35 #include "llvm/Target/TargetInstrInfo.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/ADT/BitVector.h"
39 #include "llvm/ADT/STLExtras.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/CommandLine.h"
45 ForceStackAlign("force-align-stack",
46 cl::desc("Force align the stack to the minimum alignment"
47 " needed for the function."),
48 cl::init(false), cl::Hidden);
50 X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
51 const TargetInstrInfo &tii)
52 : X86GenRegisterInfo(tm.getSubtarget<X86Subtarget>().is64Bit() ?
53 X86::ADJCALLSTACKDOWN64 :
54 X86::ADJCALLSTACKDOWN32,
55 tm.getSubtarget<X86Subtarget>().is64Bit() ?
56 X86::ADJCALLSTACKUP64 :
57 X86::ADJCALLSTACKUP32),
59 // Cache some information.
60 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
61 Is64Bit = Subtarget->is64Bit();
62 IsWin64 = Subtarget->isTargetWin64();
63 StackAlign = TM.getFrameInfo()->getStackAlignment();
76 /// getDwarfRegNum - This function maps LLVM register identifiers to the DWARF
77 /// specific numbering, used in debug info and exception tables.
78 int X86RegisterInfo::getDwarfRegNum(unsigned RegNo, bool isEH) const {
79 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
80 unsigned Flavour = DWARFFlavour::X86_64;
82 if (!Subtarget->is64Bit()) {
83 if (Subtarget->isTargetDarwin()) {
85 Flavour = DWARFFlavour::X86_32_DarwinEH;
87 Flavour = DWARFFlavour::X86_32_Generic;
88 } else if (Subtarget->isTargetCygMing()) {
89 // Unsupported by now, just quick fallback
90 Flavour = DWARFFlavour::X86_32_Generic;
92 Flavour = DWARFFlavour::X86_32_Generic;
96 return X86GenRegisterInfo::getDwarfRegNumFull(RegNo, Flavour);
99 /// getX86RegNum - This function maps LLVM register identifiers to their X86
100 /// specific numbering, which is used in various places encoding instructions.
101 unsigned X86RegisterInfo::getX86RegNum(unsigned RegNo) {
103 case X86::RAX: case X86::EAX: case X86::AX: case X86::AL: return N86::EAX;
104 case X86::RCX: case X86::ECX: case X86::CX: case X86::CL: return N86::ECX;
105 case X86::RDX: case X86::EDX: case X86::DX: case X86::DL: return N86::EDX;
106 case X86::RBX: case X86::EBX: case X86::BX: case X86::BL: return N86::EBX;
107 case X86::RSP: case X86::ESP: case X86::SP: case X86::SPL: case X86::AH:
109 case X86::RBP: case X86::EBP: case X86::BP: case X86::BPL: case X86::CH:
111 case X86::RSI: case X86::ESI: case X86::SI: case X86::SIL: case X86::DH:
113 case X86::RDI: case X86::EDI: case X86::DI: case X86::DIL: case X86::BH:
116 case X86::R8: case X86::R8D: case X86::R8W: case X86::R8B:
118 case X86::R9: case X86::R9D: case X86::R9W: case X86::R9B:
120 case X86::R10: case X86::R10D: case X86::R10W: case X86::R10B:
122 case X86::R11: case X86::R11D: case X86::R11W: case X86::R11B:
124 case X86::R12: case X86::R12D: case X86::R12W: case X86::R12B:
126 case X86::R13: case X86::R13D: case X86::R13W: case X86::R13B:
128 case X86::R14: case X86::R14D: case X86::R14W: case X86::R14B:
130 case X86::R15: case X86::R15D: case X86::R15W: case X86::R15B:
133 case X86::ST0: case X86::ST1: case X86::ST2: case X86::ST3:
134 case X86::ST4: case X86::ST5: case X86::ST6: case X86::ST7:
135 return RegNo-X86::ST0;
137 case X86::XMM0: case X86::XMM8:
138 case X86::YMM0: case X86::YMM8: case X86::MM0:
140 case X86::XMM1: case X86::XMM9:
141 case X86::YMM1: case X86::YMM9: case X86::MM1:
143 case X86::XMM2: case X86::XMM10:
144 case X86::YMM2: case X86::YMM10: case X86::MM2:
146 case X86::XMM3: case X86::XMM11:
147 case X86::YMM3: case X86::YMM11: case X86::MM3:
149 case X86::XMM4: case X86::XMM12:
150 case X86::YMM4: case X86::YMM12: case X86::MM4:
152 case X86::XMM5: case X86::XMM13:
153 case X86::YMM5: case X86::YMM13: case X86::MM5:
155 case X86::XMM6: case X86::XMM14:
156 case X86::YMM6: case X86::YMM14: case X86::MM6:
158 case X86::XMM7: case X86::XMM15:
159 case X86::YMM7: case X86::YMM15: case X86::MM7:
162 case X86::ES: return 0;
163 case X86::CS: return 1;
164 case X86::SS: return 2;
165 case X86::DS: return 3;
166 case X86::FS: return 4;
167 case X86::GS: return 5;
169 case X86::CR0: case X86::CR8 : case X86::DR0: return 0;
170 case X86::CR1: case X86::CR9 : case X86::DR1: return 1;
171 case X86::CR2: case X86::CR10: case X86::DR2: return 2;
172 case X86::CR3: case X86::CR11: case X86::DR3: return 3;
173 case X86::CR4: case X86::CR12: case X86::DR4: return 4;
174 case X86::CR5: case X86::CR13: case X86::DR5: return 5;
175 case X86::CR6: case X86::CR14: case X86::DR6: return 6;
176 case X86::CR7: case X86::CR15: case X86::DR7: return 7;
178 // Pseudo index registers are equivalent to a "none"
179 // scaled index (See Intel Manual 2A, table 2-3)
185 assert(isVirtualRegister(RegNo) && "Unknown physical register!");
186 llvm_unreachable("Register allocator hasn't allocated reg correctly yet!");
191 const TargetRegisterClass *
192 X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
193 const TargetRegisterClass *B,
194 unsigned SubIdx) const {
198 if (B == &X86::GR8RegClass) {
199 if (A->getSize() == 2 || A->getSize() == 4 || A->getSize() == 8)
201 } else if (B == &X86::GR8_ABCD_LRegClass || B == &X86::GR8_ABCD_HRegClass) {
202 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
203 A == &X86::GR64_NOREXRegClass ||
204 A == &X86::GR64_NOSPRegClass ||
205 A == &X86::GR64_NOREX_NOSPRegClass)
206 return &X86::GR64_ABCDRegClass;
207 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
208 A == &X86::GR32_NOREXRegClass ||
209 A == &X86::GR32_NOSPRegClass)
210 return &X86::GR32_ABCDRegClass;
211 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
212 A == &X86::GR16_NOREXRegClass)
213 return &X86::GR16_ABCDRegClass;
214 } else if (B == &X86::GR8_NOREXRegClass) {
215 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
216 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
217 return &X86::GR64_NOREXRegClass;
218 else if (A == &X86::GR64_ABCDRegClass)
219 return &X86::GR64_ABCDRegClass;
220 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
221 A == &X86::GR32_NOSPRegClass)
222 return &X86::GR32_NOREXRegClass;
223 else if (A == &X86::GR32_ABCDRegClass)
224 return &X86::GR32_ABCDRegClass;
225 else if (A == &X86::GR16RegClass || A == &X86::GR16_NOREXRegClass)
226 return &X86::GR16_NOREXRegClass;
227 else if (A == &X86::GR16_ABCDRegClass)
228 return &X86::GR16_ABCDRegClass;
231 case X86::sub_8bit_hi:
232 if (B == &X86::GR8_ABCD_HRegClass) {
233 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
234 A == &X86::GR64_NOREXRegClass ||
235 A == &X86::GR64_NOSPRegClass ||
236 A == &X86::GR64_NOREX_NOSPRegClass)
237 return &X86::GR64_ABCDRegClass;
238 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
239 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
240 return &X86::GR32_ABCDRegClass;
241 else if (A == &X86::GR16RegClass || A == &X86::GR16_ABCDRegClass ||
242 A == &X86::GR16_NOREXRegClass)
243 return &X86::GR16_ABCDRegClass;
247 if (B == &X86::GR16RegClass) {
248 if (A->getSize() == 4 || A->getSize() == 8)
250 } else if (B == &X86::GR16_ABCDRegClass) {
251 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
252 A == &X86::GR64_NOREXRegClass ||
253 A == &X86::GR64_NOSPRegClass ||
254 A == &X86::GR64_NOREX_NOSPRegClass)
255 return &X86::GR64_ABCDRegClass;
256 else if (A == &X86::GR32RegClass || A == &X86::GR32_ABCDRegClass ||
257 A == &X86::GR32_NOREXRegClass || A == &X86::GR32_NOSPRegClass)
258 return &X86::GR32_ABCDRegClass;
259 } else if (B == &X86::GR16_NOREXRegClass) {
260 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
261 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
262 return &X86::GR64_NOREXRegClass;
263 else if (A == &X86::GR64_ABCDRegClass)
264 return &X86::GR64_ABCDRegClass;
265 else if (A == &X86::GR32RegClass || A == &X86::GR32_NOREXRegClass ||
266 A == &X86::GR32_NOSPRegClass)
267 return &X86::GR32_NOREXRegClass;
268 else if (A == &X86::GR32_ABCDRegClass)
269 return &X86::GR64_ABCDRegClass;
273 if (B == &X86::GR32RegClass || B == &X86::GR32_NOSPRegClass) {
274 if (A->getSize() == 8)
276 } else if (B == &X86::GR32_ABCDRegClass) {
277 if (A == &X86::GR64RegClass || A == &X86::GR64_ABCDRegClass ||
278 A == &X86::GR64_NOREXRegClass ||
279 A == &X86::GR64_NOSPRegClass ||
280 A == &X86::GR64_NOREX_NOSPRegClass)
281 return &X86::GR64_ABCDRegClass;
282 } else if (B == &X86::GR32_NOREXRegClass) {
283 if (A == &X86::GR64RegClass || A == &X86::GR64_NOREXRegClass ||
284 A == &X86::GR64_NOSPRegClass || A == &X86::GR64_NOREX_NOSPRegClass)
285 return &X86::GR64_NOREXRegClass;
286 else if (A == &X86::GR64_ABCDRegClass)
287 return &X86::GR64_ABCDRegClass;
291 if (B == &X86::FR32RegClass)
295 if (B == &X86::FR64RegClass)
299 if (B == &X86::VR128RegClass)
306 const TargetRegisterClass *
307 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
309 default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
310 case 0: // Normal GPRs.
311 if (TM.getSubtarget<X86Subtarget>().is64Bit())
312 return &X86::GR64RegClass;
313 return &X86::GR32RegClass;
314 case 1: // Normal GRPs except the stack pointer (for encoding reasons).
315 if (TM.getSubtarget<X86Subtarget>().is64Bit())
316 return &X86::GR64_NOSPRegClass;
317 return &X86::GR32_NOSPRegClass;
321 const TargetRegisterClass *
322 X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
323 if (RC == &X86::CCRRegClass) {
325 return &X86::GR64RegClass;
327 return &X86::GR32RegClass;
333 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
334 bool callsEHReturn = false;
335 bool ghcCall = false;
338 callsEHReturn = MF->getMMI().callsEHReturn();
339 const Function *F = MF->getFunction();
340 ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
343 static const unsigned GhcCalleeSavedRegs[] = {
347 static const unsigned CalleeSavedRegs32Bit[] = {
348 X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
351 static const unsigned CalleeSavedRegs32EHRet[] = {
352 X86::EAX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
355 static const unsigned CalleeSavedRegs64Bit[] = {
356 X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
359 static const unsigned CalleeSavedRegs64EHRet[] = {
360 X86::RAX, X86::RDX, X86::RBX, X86::R12,
361 X86::R13, X86::R14, X86::R15, X86::RBP, 0
364 static const unsigned CalleeSavedRegsWin64[] = {
365 X86::RBX, X86::RBP, X86::RDI, X86::RSI,
366 X86::R12, X86::R13, X86::R14, X86::R15,
367 X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
368 X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
369 X86::XMM14, X86::XMM15, 0
373 return GhcCalleeSavedRegs;
374 } else if (Is64Bit) {
376 return CalleeSavedRegsWin64;
378 return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
380 return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
384 BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
385 BitVector Reserved(getNumRegs());
386 // Set the stack-pointer register and its aliases as reserved.
387 Reserved.set(X86::RSP);
388 Reserved.set(X86::ESP);
389 Reserved.set(X86::SP);
390 Reserved.set(X86::SPL);
392 // Set the instruction pointer register and its aliases as reserved.
393 Reserved.set(X86::RIP);
394 Reserved.set(X86::EIP);
395 Reserved.set(X86::IP);
397 // Set the frame-pointer register and its aliases as reserved if needed.
399 Reserved.set(X86::RBP);
400 Reserved.set(X86::EBP);
401 Reserved.set(X86::BP);
402 Reserved.set(X86::BPL);
405 // Mark the x87 stack registers as reserved, since they don't behave normally
406 // with respect to liveness. We don't fully model the effects of x87 stack
407 // pushes and pops after stackification.
408 Reserved.set(X86::ST0);
409 Reserved.set(X86::ST1);
410 Reserved.set(X86::ST2);
411 Reserved.set(X86::ST3);
412 Reserved.set(X86::ST4);
413 Reserved.set(X86::ST5);
414 Reserved.set(X86::ST6);
415 Reserved.set(X86::ST7);
419 //===----------------------------------------------------------------------===//
420 // Stack Frame Processing methods
421 //===----------------------------------------------------------------------===//
423 /// hasFP - Return true if the specified function should have a dedicated frame
424 /// pointer register. This is true if the function has variable sized allocas
425 /// or if frame pointer elimination is disabled.
426 bool X86RegisterInfo::hasFP(const MachineFunction &MF) const {
427 const MachineFrameInfo *MFI = MF.getFrameInfo();
428 const MachineModuleInfo &MMI = MF.getMMI();
430 return (DisableFramePointerElim(MF) ||
431 needsStackRealignment(MF) ||
432 MFI->hasVarSizedObjects() ||
433 MFI->isFrameAddressTaken() ||
434 MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
435 MMI.callsUnwindInit());
438 bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const {
439 const MachineFrameInfo *MFI = MF.getFrameInfo();
440 return (RealignStack &&
441 !MFI->hasVarSizedObjects());
444 bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
445 const MachineFrameInfo *MFI = MF.getFrameInfo();
446 const Function *F = MF.getFunction();
447 bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
448 F->hasFnAttr(Attribute::StackAlignment));
450 // FIXME: Currently we don't support stack realignment for functions with
451 // variable-sized allocas.
452 // FIXME: It's more complicated than this...
453 if (0 && requiresRealignment && MFI->hasVarSizedObjects())
455 "Stack realignment in presense of dynamic allocas is not supported");
457 // If we've requested that we force align the stack do so now.
459 return canRealignStack(MF);
461 return requiresRealignment && canRealignStack(MF);
464 bool X86RegisterInfo::hasReservedCallFrame(const MachineFunction &MF) const {
465 return !MF.getFrameInfo()->hasVarSizedObjects();
468 bool X86RegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
469 unsigned Reg, int &FrameIdx) const {
470 if (Reg == FramePtr && hasFP(MF)) {
471 FrameIdx = MF.getFrameInfo()->getObjectIndexBegin();
478 X86RegisterInfo::getFrameIndexOffset(const MachineFunction &MF, int FI) const {
479 const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
480 const MachineFrameInfo *MFI = MF.getFrameInfo();
481 int Offset = MFI->getObjectOffset(FI) - TFI.getOffsetOfLocalArea();
482 uint64_t StackSize = MFI->getStackSize();
484 if (needsStackRealignment(MF)) {
486 // Skip the saved EBP.
489 unsigned Align = MFI->getObjectAlignment(FI);
490 assert((-(Offset + StackSize)) % Align == 0);
492 return Offset + StackSize;
494 // FIXME: Support tail calls
497 return Offset + StackSize;
499 // Skip the saved EBP.
502 // Skip the RETADDR move area
503 const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
504 int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
505 if (TailCallReturnAddrDelta < 0)
506 Offset -= TailCallReturnAddrDelta;
512 static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
515 return X86::SUB64ri8;
516 return X86::SUB64ri32;
519 return X86::SUB32ri8;
524 static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
527 return X86::ADD64ri8;
528 return X86::ADD64ri32;
531 return X86::ADD32ri8;
536 void X86RegisterInfo::
537 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
538 MachineBasicBlock::iterator I) const {
539 if (!hasReservedCallFrame(MF)) {
540 // If the stack pointer can be changed after prologue, turn the
541 // adjcallstackup instruction into a 'sub ESP, <amt>' and the
542 // adjcallstackdown instruction into 'add ESP, <amt>'
543 // TODO: consider using push / pop instead of sub + store / add
544 MachineInstr *Old = I;
545 uint64_t Amount = Old->getOperand(0).getImm();
547 // We need to keep the stack aligned properly. To do this, we round the
548 // amount of space needed for the outgoing arguments up to the next
549 // alignment boundary.
550 Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
552 MachineInstr *New = 0;
553 if (Old->getOpcode() == getCallFrameSetupOpcode()) {
554 New = BuildMI(MF, Old->getDebugLoc(),
555 TII.get(getSUBriOpcode(Is64Bit, Amount)),
560 assert(Old->getOpcode() == getCallFrameDestroyOpcode());
562 // Factor out the amount the callee already popped.
563 uint64_t CalleeAmt = Old->getOperand(1).getImm();
567 unsigned Opc = getADDriOpcode(Is64Bit, Amount);
568 New = BuildMI(MF, Old->getDebugLoc(), TII.get(Opc), StackPtr)
575 // The EFLAGS implicit def is dead.
576 New->getOperand(3).setIsDead();
578 // Replace the pseudo instruction with a new instruction.
582 } else if (I->getOpcode() == getCallFrameDestroyOpcode()) {
583 // If we are performing frame pointer elimination and if the callee pops
584 // something off the stack pointer, add it back. We do this until we have
585 // more advanced stack pointer tracking ability.
586 if (uint64_t CalleeAmt = I->getOperand(1).getImm()) {
587 unsigned Opc = getSUBriOpcode(Is64Bit, CalleeAmt);
588 MachineInstr *Old = I;
590 BuildMI(MF, Old->getDebugLoc(), TII.get(Opc),
595 // The EFLAGS implicit def is dead.
596 New->getOperand(3).setIsDead();
605 X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
606 int SPAdj, RegScavenger *RS) const{
607 assert(SPAdj == 0 && "Unexpected");
610 MachineInstr &MI = *II;
611 MachineFunction &MF = *MI.getParent()->getParent();
613 while (!MI.getOperand(i).isFI()) {
615 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
618 int FrameIndex = MI.getOperand(i).getIndex();
621 unsigned Opc = MI.getOpcode();
622 bool AfterFPPop = Opc == X86::TAILJMPm64 || Opc == X86::TAILJMPm;
623 if (needsStackRealignment(MF))
624 BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
628 BasePtr = (hasFP(MF) ? FramePtr : StackPtr);
630 // This must be part of a four operand memory reference. Replace the
631 // FrameIndex with base register with EBP. Add an offset to the offset.
632 MI.getOperand(i).ChangeToRegister(BasePtr, false);
634 // Now add the frame object offset to the offset from EBP.
637 // Tail call jmp happens after FP is popped.
638 const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
639 const MachineFrameInfo *MFI = MF.getFrameInfo();
640 FIOffset = MFI->getObjectOffset(FrameIndex) - TFI.getOffsetOfLocalArea();
642 FIOffset = getFrameIndexOffset(MF, FrameIndex);
644 if (MI.getOperand(i+3).isImm()) {
645 // Offset is a 32-bit integer.
646 int Offset = FIOffset + (int)(MI.getOperand(i + 3).getImm());
647 MI.getOperand(i + 3).ChangeToImmediate(Offset);
649 // Offset is symbolic. This is extremely rare.
650 uint64_t Offset = FIOffset + (uint64_t)MI.getOperand(i+3).getOffset();
651 MI.getOperand(i+3).setOffset(Offset);
656 X86RegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
657 RegScavenger *RS) const {
658 MachineFrameInfo *MFI = MF.getFrameInfo();
660 X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
661 int32_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
663 if (TailCallReturnAddrDelta < 0) {
664 // create RETURNADDR area
673 MFI->CreateFixedObject(-TailCallReturnAddrDelta,
674 (-1U*SlotSize)+TailCallReturnAddrDelta, true);
678 assert((TailCallReturnAddrDelta <= 0) &&
679 "The Delta should always be zero or negative");
680 const TargetFrameInfo &TFI = *MF.getTarget().getFrameInfo();
682 // Create a frame entry for the EBP register that must be saved.
683 int FrameIdx = MFI->CreateFixedObject(SlotSize,
685 TFI.getOffsetOfLocalArea() +
686 TailCallReturnAddrDelta,
688 assert(FrameIdx == MFI->getObjectIndexBegin() &&
689 "Slot for EBP register must be last in order to be found!");
694 /// emitSPUpdate - Emit a series of instructions to increment / decrement the
695 /// stack pointer by a constant value.
697 void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
698 unsigned StackPtr, int64_t NumBytes, bool Is64Bit,
699 const TargetInstrInfo &TII) {
700 bool isSub = NumBytes < 0;
701 uint64_t Offset = isSub ? -NumBytes : NumBytes;
702 unsigned Opc = isSub ?
703 getSUBriOpcode(Is64Bit, Offset) :
704 getADDriOpcode(Is64Bit, Offset);
705 uint64_t Chunk = (1LL << 31) - 1;
706 DebugLoc DL = MBB.findDebugLoc(MBBI);
709 uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset;
711 BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
714 MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
719 /// mergeSPUpdatesUp - Merge two stack-manipulating instructions upper iterator.
721 void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
722 unsigned StackPtr, uint64_t *NumBytes = NULL) {
723 if (MBBI == MBB.begin()) return;
725 MachineBasicBlock::iterator PI = prior(MBBI);
726 unsigned Opc = PI->getOpcode();
727 if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
728 Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
729 PI->getOperand(0).getReg() == StackPtr) {
731 *NumBytes += PI->getOperand(2).getImm();
733 } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
734 Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
735 PI->getOperand(0).getReg() == StackPtr) {
737 *NumBytes -= PI->getOperand(2).getImm();
742 /// mergeSPUpdatesDown - Merge two stack-manipulating instructions lower iterator.
744 void mergeSPUpdatesDown(MachineBasicBlock &MBB,
745 MachineBasicBlock::iterator &MBBI,
746 unsigned StackPtr, uint64_t *NumBytes = NULL) {
747 // FIXME: THIS ISN'T RUN!!!
750 if (MBBI == MBB.end()) return;
752 MachineBasicBlock::iterator NI = llvm::next(MBBI);
753 if (NI == MBB.end()) return;
755 unsigned Opc = NI->getOpcode();
756 if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
757 Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
758 NI->getOperand(0).getReg() == StackPtr) {
760 *NumBytes -= NI->getOperand(2).getImm();
763 } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
764 Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
765 NI->getOperand(0).getReg() == StackPtr) {
767 *NumBytes += NI->getOperand(2).getImm();
773 /// mergeSPUpdates - Checks the instruction before/after the passed
774 /// instruction. If it is an ADD/SUB instruction it is deleted argument and the
775 /// stack adjustment is returned as a positive value for ADD and a negative for
777 static int mergeSPUpdates(MachineBasicBlock &MBB,
778 MachineBasicBlock::iterator &MBBI,
780 bool doMergeWithPrevious) {
781 if ((doMergeWithPrevious && MBBI == MBB.begin()) ||
782 (!doMergeWithPrevious && MBBI == MBB.end()))
785 MachineBasicBlock::iterator PI = doMergeWithPrevious ? prior(MBBI) : MBBI;
786 MachineBasicBlock::iterator NI = doMergeWithPrevious ? 0 : llvm::next(MBBI);
787 unsigned Opc = PI->getOpcode();
790 if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
791 Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
792 PI->getOperand(0).getReg() == StackPtr){
793 Offset += PI->getOperand(2).getImm();
795 if (!doMergeWithPrevious) MBBI = NI;
796 } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
797 Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
798 PI->getOperand(0).getReg() == StackPtr) {
799 Offset -= PI->getOperand(2).getImm();
801 if (!doMergeWithPrevious) MBBI = NI;
807 void X86RegisterInfo::emitCalleeSavedFrameMoves(MachineFunction &MF,
809 unsigned FramePtr) const {
810 MachineFrameInfo *MFI = MF.getFrameInfo();
811 MachineModuleInfo &MMI = MF.getMMI();
813 // Add callee saved registers to move list.
814 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
815 if (CSI.empty()) return;
817 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
818 const TargetData *TD = MF.getTarget().getTargetData();
819 bool HasFP = hasFP(MF);
821 // Calculate amount of bytes used for return address storing.
823 (MF.getTarget().getFrameInfo()->getStackGrowthDirection() ==
824 TargetFrameInfo::StackGrowsUp ?
825 TD->getPointerSize() : -TD->getPointerSize());
827 // FIXME: This is dirty hack. The code itself is pretty mess right now.
828 // It should be rewritten from scratch and generalized sometimes.
830 // Determine maximum offset (minumum due to stack growth).
831 int64_t MaxOffset = 0;
832 for (std::vector<CalleeSavedInfo>::const_iterator
833 I = CSI.begin(), E = CSI.end(); I != E; ++I)
834 MaxOffset = std::min(MaxOffset,
835 MFI->getObjectOffset(I->getFrameIdx()));
837 // Calculate offsets.
838 int64_t saveAreaOffset = (HasFP ? 3 : 2) * stackGrowth;
839 for (std::vector<CalleeSavedInfo>::const_iterator
840 I = CSI.begin(), E = CSI.end(); I != E; ++I) {
841 int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
842 unsigned Reg = I->getReg();
843 Offset = MaxOffset - Offset + saveAreaOffset;
845 // Don't output a new machine move if we're re-saving the frame
846 // pointer. This happens when the PrologEpilogInserter has inserted an extra
847 // "PUSH" of the frame pointer -- the "emitPrologue" method automatically
848 // generates one when frame pointers are used. If we generate a "machine
849 // move" for this extra "PUSH", the linker will lose track of the fact that
850 // the frame pointer should have the value of the first "PUSH" when it's
853 // FIXME: This looks inelegant. It's possibly correct, but it's covering up
854 // another bug. I.e., one where we generate a prolog like this:
862 // The immediate re-push of EBP is unnecessary. At the least, it's an
863 // optimization bug. EBP can be used as a scratch register in certain
864 // cases, but probably not when we have a frame pointer.
865 if (HasFP && FramePtr == Reg)
868 MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
869 MachineLocation CSSrc(Reg);
870 Moves.push_back(MachineMove(Label, CSDst, CSSrc));
874 /// emitPrologue - Push callee-saved registers onto the stack, which
875 /// automatically adjust the stack pointer. Adjust the stack pointer to allocate
876 /// space for local variables. Also emit labels used by the exception handler to
877 /// generate the exception handling frames.
878 void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
879 MachineBasicBlock &MBB = MF.front(); // Prologue goes in entry BB.
880 MachineBasicBlock::iterator MBBI = MBB.begin();
881 MachineFrameInfo *MFI = MF.getFrameInfo();
882 const Function *Fn = MF.getFunction();
883 const X86Subtarget *Subtarget = &MF.getTarget().getSubtarget<X86Subtarget>();
884 MachineModuleInfo &MMI = MF.getMMI();
885 X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
886 bool needsFrameMoves = MMI.hasDebugInfo() ||
887 !Fn->doesNotThrow() || UnwindTablesMandatory;
888 uint64_t MaxAlign = MFI->getMaxAlignment(); // Desired stack alignment.
889 uint64_t StackSize = MFI->getStackSize(); // Number of bytes to allocate.
890 bool HasFP = hasFP(MF);
893 // If we're forcing a stack realignment we can't rely on just the frame
894 // info, we need to know the ABI stack alignment as well in case we
895 // have a call out. Otherwise just make sure we have some alignment - we'll
896 // go with the minimum SlotSize.
897 if (ForceStackAlign) {
899 MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
900 else if (MaxAlign < SlotSize)
904 // Add RETADDR move area to callee saved frame size.
905 int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
906 if (TailCallReturnAddrDelta < 0)
907 X86FI->setCalleeSavedFrameSize(
908 X86FI->getCalleeSavedFrameSize() - TailCallReturnAddrDelta);
910 // If this is x86-64 and the Red Zone is not disabled, if we are a leaf
911 // function, and use up to 128 bytes of stack space, don't have a frame
912 // pointer, calls, or dynamic alloca then we do not need to adjust the
913 // stack pointer (we fit in the Red Zone).
914 if (Is64Bit && !Fn->hasFnAttr(Attribute::NoRedZone) &&
915 !needsStackRealignment(MF) &&
916 !MFI->hasVarSizedObjects() && // No dynamic alloca.
917 !MFI->adjustsStack() && // No calls.
918 !Subtarget->isTargetWin64()) { // Win64 has no Red Zone
919 uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
920 if (HasFP) MinSize += SlotSize;
921 StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0);
922 MFI->setStackSize(StackSize);
923 } else if (Subtarget->isTargetWin64()) {
924 // We need to always allocate 32 bytes as register spill area.
925 // FIXME: We might reuse these 32 bytes for leaf functions.
927 MFI->setStackSize(StackSize);
930 // Insert stack pointer adjustment for later moving of return addr. Only
931 // applies to tail call optimized functions where the callee argument stack
932 // size is bigger than the callers.
933 if (TailCallReturnAddrDelta < 0) {
935 BuildMI(MBB, MBBI, DL,
936 TII.get(getSUBriOpcode(Is64Bit, -TailCallReturnAddrDelta)),
939 .addImm(-TailCallReturnAddrDelta);
940 MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
943 // Mapping for machine moves:
945 // DST: VirtualFP AND
946 // SRC: VirtualFP => DW_CFA_def_cfa_offset
947 // ELSE => DW_CFA_def_cfa
949 // SRC: VirtualFP AND
950 // DST: Register => DW_CFA_def_cfa_register
953 // OFFSET < 0 => DW_CFA_offset_extended_sf
954 // REG < 64 => DW_CFA_offset + Reg
955 // ELSE => DW_CFA_offset_extended
957 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
958 const TargetData *TD = MF.getTarget().getTargetData();
959 uint64_t NumBytes = 0;
960 int stackGrowth = -TD->getPointerSize();
963 // Calculate required stack adjustment.
964 uint64_t FrameSize = StackSize - SlotSize;
965 if (needsStackRealignment(MF))
966 FrameSize = (FrameSize + MaxAlign - 1) / MaxAlign * MaxAlign;
968 NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
970 // Get the offset of the stack slot for the EBP register, which is
971 // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
972 // Update the frame offset adjustment.
973 MFI->setOffsetAdjustment(-NumBytes);
975 // Save EBP/RBP into the appropriate stack slot.
976 BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
977 .addReg(FramePtr, RegState::Kill);
979 if (needsFrameMoves) {
980 // Mark the place where EBP/RBP was saved.
981 MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
982 BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(FrameLabel);
984 // Define the current CFA rule to use the provided offset.
986 MachineLocation SPDst(MachineLocation::VirtualFP);
987 MachineLocation SPSrc(MachineLocation::VirtualFP, 2 * stackGrowth);
988 Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
990 // FIXME: Verify & implement for FP
991 MachineLocation SPDst(StackPtr);
992 MachineLocation SPSrc(StackPtr, stackGrowth);
993 Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
996 // Change the rule for the FramePtr to be an "offset" rule.
997 MachineLocation FPDst(MachineLocation::VirtualFP, 2 * stackGrowth);
998 MachineLocation FPSrc(FramePtr);
999 Moves.push_back(MachineMove(FrameLabel, FPDst, FPSrc));
1002 // Update EBP with the new base value...
1003 BuildMI(MBB, MBBI, DL,
1004 TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), FramePtr)
1007 if (needsFrameMoves) {
1008 // Mark effective beginning of when frame pointer becomes valid.
1009 MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
1010 BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(FrameLabel);
1012 // Define the current CFA to use the EBP/RBP register.
1013 MachineLocation FPDst(FramePtr);
1014 MachineLocation FPSrc(MachineLocation::VirtualFP);
1015 Moves.push_back(MachineMove(FrameLabel, FPDst, FPSrc));
1018 // Mark the FramePtr as live-in in every block except the entry.
1019 for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
1021 I->addLiveIn(FramePtr);
1024 if (needsStackRealignment(MF)) {
1026 BuildMI(MBB, MBBI, DL,
1027 TII.get(Is64Bit ? X86::AND64ri32 : X86::AND32ri),
1028 StackPtr).addReg(StackPtr).addImm(-MaxAlign);
1030 // The EFLAGS implicit def is dead.
1031 MI->getOperand(3).setIsDead();
1034 NumBytes = StackSize - X86FI->getCalleeSavedFrameSize();
1037 // Skip the callee-saved push instructions.
1038 bool PushedRegs = false;
1039 int StackOffset = 2 * stackGrowth;
1041 while (MBBI != MBB.end() &&
1042 (MBBI->getOpcode() == X86::PUSH32r ||
1043 MBBI->getOpcode() == X86::PUSH64r)) {
1047 if (!HasFP && needsFrameMoves) {
1048 // Mark callee-saved push instruction.
1049 MCSymbol *Label = MMI.getContext().CreateTempSymbol();
1050 BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(Label);
1052 // Define the current CFA rule to use the provided offset.
1053 unsigned Ptr = StackSize ?
1054 MachineLocation::VirtualFP : StackPtr;
1055 MachineLocation SPDst(Ptr);
1056 MachineLocation SPSrc(Ptr, StackOffset);
1057 Moves.push_back(MachineMove(Label, SPDst, SPSrc));
1058 StackOffset += stackGrowth;
1062 DL = MBB.findDebugLoc(MBBI);
1064 // Adjust stack pointer: ESP -= numbytes.
1066 // Windows and cygwin/mingw require a prologue helper routine when allocating
1067 // more than 4K bytes on the stack. Windows uses __chkstk and cygwin/mingw
1068 // uses __alloca. __alloca and the 32-bit version of __chkstk will probe
1069 // the stack and adjust the stack pointer in one go. The 64-bit version
1070 // of __chkstk is only responsible for probing the stack. The 64-bit
1071 // prologue is responsible for adjusting the stack pointer. Touching the
1072 // stack at 4K increments is necessary to ensure that the guard pages used
1073 // by the OS virtual memory manager are allocated in correct sequence.
1074 if (NumBytes >= 4096 &&
1075 (Subtarget->isTargetCygMing() || Subtarget->isTargetWin32())) {
1076 // Check, whether EAX is livein for this function.
1077 bool isEAXAlive = false;
1078 for (MachineRegisterInfo::livein_iterator
1079 II = MF.getRegInfo().livein_begin(),
1080 EE = MF.getRegInfo().livein_end(); (II != EE) && !isEAXAlive; ++II) {
1081 unsigned Reg = II->first;
1082 isEAXAlive = (Reg == X86::EAX || Reg == X86::AX ||
1083 Reg == X86::AH || Reg == X86::AL);
1087 const char *StackProbeSymbol =
1088 Subtarget->isTargetWindows() ? "_chkstk" : "_alloca";
1089 unsigned CallOp = Is64Bit ? X86::CALL64pcrel32 : X86::CALLpcrel32;
1091 BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
1093 BuildMI(MBB, MBBI, DL, TII.get(CallOp))
1094 .addExternalSymbol(StackProbeSymbol)
1095 .addReg(StackPtr, RegState::Define | RegState::Implicit)
1096 .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
1099 BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
1100 .addReg(X86::EAX, RegState::Kill);
1102 // Allocate NumBytes-4 bytes on stack. We'll also use 4 already
1103 // allocated bytes for EAX.
1104 BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
1105 .addImm(NumBytes - 4);
1106 BuildMI(MBB, MBBI, DL, TII.get(CallOp))
1107 .addExternalSymbol(StackProbeSymbol)
1108 .addReg(StackPtr, RegState::Define | RegState::Implicit)
1109 .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
1112 MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
1114 StackPtr, false, NumBytes - 4);
1115 MBB.insert(MBBI, MI);
1117 } else if (NumBytes) {
1118 // If there is an SUB32ri of ESP immediately before this instruction, merge
1119 // the two. This can be the case when tail call elimination is enabled and
1120 // the callee has more arguments then the caller.
1121 NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
1123 // If there is an ADD32ri or SUB32ri of ESP immediately after this
1124 // instruction, merge the two instructions.
1125 mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
1128 emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
1131 if ((NumBytes || PushedRegs) && needsFrameMoves) {
1132 // Mark end of stack pointer adjustment.
1133 MCSymbol *Label = MMI.getContext().CreateTempSymbol();
1134 BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(Label);
1136 if (!HasFP && NumBytes) {
1137 // Define the current CFA rule to use the provided offset.
1139 MachineLocation SPDst(MachineLocation::VirtualFP);
1140 MachineLocation SPSrc(MachineLocation::VirtualFP,
1141 -StackSize + stackGrowth);
1142 Moves.push_back(MachineMove(Label, SPDst, SPSrc));
1144 // FIXME: Verify & implement for FP
1145 MachineLocation SPDst(StackPtr);
1146 MachineLocation SPSrc(StackPtr, stackGrowth);
1147 Moves.push_back(MachineMove(Label, SPDst, SPSrc));
1151 // Emit DWARF info specifying the offsets of the callee-saved registers.
1153 emitCalleeSavedFrameMoves(MF, Label, HasFP ? FramePtr : StackPtr);
1157 void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
1158 MachineBasicBlock &MBB) const {
1159 const MachineFrameInfo *MFI = MF.getFrameInfo();
1160 X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
1161 MachineBasicBlock::iterator MBBI = prior(MBB.end());
1162 unsigned RetOpcode = MBBI->getOpcode();
1163 DebugLoc DL = MBBI->getDebugLoc();
1165 switch (RetOpcode) {
1167 llvm_unreachable("Can only insert epilog into returning blocks");
1170 case X86::TCRETURNdi:
1171 case X86::TCRETURNri:
1172 case X86::TCRETURNmi:
1173 case X86::TCRETURNdi64:
1174 case X86::TCRETURNri64:
1175 case X86::TCRETURNmi64:
1176 case X86::EH_RETURN:
1177 case X86::EH_RETURN64:
1178 break; // These are ok
1181 // Get the number of bytes to allocate from the FrameInfo.
1182 uint64_t StackSize = MFI->getStackSize();
1183 uint64_t MaxAlign = MFI->getMaxAlignment();
1184 unsigned CSSize = X86FI->getCalleeSavedFrameSize();
1185 uint64_t NumBytes = 0;
1187 // If we're forcing a stack realignment we can't rely on just the frame
1188 // info, we need to know the ABI stack alignment as well in case we
1189 // have a call out. Otherwise just make sure we have some alignment - we'll
1190 // go with the minimum.
1191 if (ForceStackAlign) {
1192 if (MFI->hasCalls())
1193 MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
1195 MaxAlign = MaxAlign ? MaxAlign : 4;
1199 // Calculate required stack adjustment.
1200 uint64_t FrameSize = StackSize - SlotSize;
1201 if (needsStackRealignment(MF))
1202 FrameSize = (FrameSize + MaxAlign - 1)/MaxAlign*MaxAlign;
1204 NumBytes = FrameSize - CSSize;
1207 BuildMI(MBB, MBBI, DL,
1208 TII.get(Is64Bit ? X86::POP64r : X86::POP32r), FramePtr);
1210 NumBytes = StackSize - CSSize;
1213 // Skip the callee-saved pop instructions.
1214 MachineBasicBlock::iterator LastCSPop = MBBI;
1215 while (MBBI != MBB.begin()) {
1216 MachineBasicBlock::iterator PI = prior(MBBI);
1217 unsigned Opc = PI->getOpcode();
1219 if (Opc != X86::POP32r && Opc != X86::POP64r &&
1220 !PI->getDesc().isTerminator())
1226 DL = MBBI->getDebugLoc();
1228 // If there is an ADD32ri or SUB32ri of ESP immediately before this
1229 // instruction, merge the two instructions.
1230 if (NumBytes || MFI->hasVarSizedObjects())
1231 mergeSPUpdatesUp(MBB, MBBI, StackPtr, &NumBytes);
1233 // If dynamic alloca is used, then reset esp to point to the last callee-saved
1234 // slot before popping them off! Same applies for the case, when stack was
1236 if (needsStackRealignment(MF)) {
1237 // We cannot use LEA here, because stack pointer was realigned. We need to
1238 // deallocate local frame back.
1240 emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII);
1241 MBBI = prior(LastCSPop);
1244 BuildMI(MBB, MBBI, DL,
1245 TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
1246 StackPtr).addReg(FramePtr);
1247 } else if (MFI->hasVarSizedObjects()) {
1249 unsigned Opc = Is64Bit ? X86::LEA64r : X86::LEA32r;
1251 addRegOffset(BuildMI(MF, DL, TII.get(Opc), StackPtr),
1252 FramePtr, false, -CSSize);
1253 MBB.insert(MBBI, MI);
1255 BuildMI(MBB, MBBI, DL,
1256 TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), StackPtr)
1259 } else if (NumBytes) {
1260 // Adjust stack pointer back: ESP += numbytes.
1261 emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII);
1264 // We're returning from function via eh_return.
1265 if (RetOpcode == X86::EH_RETURN || RetOpcode == X86::EH_RETURN64) {
1266 MBBI = prior(MBB.end());
1267 MachineOperand &DestAddr = MBBI->getOperand(0);
1268 assert(DestAddr.isReg() && "Offset should be in register!");
1269 BuildMI(MBB, MBBI, DL,
1270 TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
1271 StackPtr).addReg(DestAddr.getReg());
1272 } else if (RetOpcode == X86::TCRETURNri || RetOpcode == X86::TCRETURNdi ||
1273 RetOpcode == X86::TCRETURNmi ||
1274 RetOpcode == X86::TCRETURNri64 || RetOpcode == X86::TCRETURNdi64 ||
1275 RetOpcode == X86::TCRETURNmi64) {
1276 bool isMem = RetOpcode == X86::TCRETURNmi || RetOpcode == X86::TCRETURNmi64;
1277 // Tail call return: adjust the stack pointer and jump to callee.
1278 MBBI = prior(MBB.end());
1279 MachineOperand &JumpTarget = MBBI->getOperand(0);
1280 MachineOperand &StackAdjust = MBBI->getOperand(isMem ? 5 : 1);
1281 assert(StackAdjust.isImm() && "Expecting immediate value.");
1283 // Adjust stack pointer.
1284 int StackAdj = StackAdjust.getImm();
1285 int MaxTCDelta = X86FI->getTCReturnAddrDelta();
1287 assert(MaxTCDelta <= 0 && "MaxTCDelta should never be positive");
1289 // Incoporate the retaddr area.
1290 Offset = StackAdj-MaxTCDelta;
1291 assert(Offset >= 0 && "Offset should never be negative");
1294 // Check for possible merge with preceeding ADD instruction.
1295 Offset += mergeSPUpdates(MBB, MBBI, StackPtr, true);
1296 emitSPUpdate(MBB, MBBI, StackPtr, Offset, Is64Bit, TII);
1299 // Jump to label or value in register.
1300 if (RetOpcode == X86::TCRETURNdi || RetOpcode == X86::TCRETURNdi64) {
1301 BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNdi)
1302 ? X86::TAILJMPd : X86::TAILJMPd64)).
1303 addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
1304 JumpTarget.getTargetFlags());
1305 } else if (RetOpcode == X86::TCRETURNmi || RetOpcode == X86::TCRETURNmi64) {
1306 MachineInstrBuilder MIB =
1307 BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNmi)
1308 ? X86::TAILJMPm : X86::TAILJMPm64));
1309 for (unsigned i = 0; i != 5; ++i)
1310 MIB.addOperand(MBBI->getOperand(i));
1311 } else if (RetOpcode == X86::TCRETURNri64) {
1312 BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr64)).
1313 addReg(JumpTarget.getReg(), RegState::Kill);
1315 BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr)).
1316 addReg(JumpTarget.getReg(), RegState::Kill);
1319 MachineInstr *NewMI = prior(MBBI);
1320 for (unsigned i = 2, e = MBBI->getNumOperands(); i != e; ++i)
1321 NewMI->addOperand(MBBI->getOperand(i));
1323 // Delete the pseudo instruction TCRETURN.
1325 } else if ((RetOpcode == X86::RET || RetOpcode == X86::RETI) &&
1326 (X86FI->getTCReturnAddrDelta() < 0)) {
1327 // Add the return addr area delta back since we are not tail calling.
1328 int delta = -1*X86FI->getTCReturnAddrDelta();
1329 MBBI = prior(MBB.end());
1331 // Check for possible merge with preceeding ADD instruction.
1332 delta += mergeSPUpdates(MBB, MBBI, StackPtr, true);
1333 emitSPUpdate(MBB, MBBI, StackPtr, delta, Is64Bit, TII);
1337 unsigned X86RegisterInfo::getRARegister() const {
1338 return Is64Bit ? X86::RIP // Should have dwarf #16.
1339 : X86::EIP; // Should have dwarf #8.
1342 unsigned X86RegisterInfo::getFrameRegister(const MachineFunction &MF) const {
1343 return hasFP(MF) ? FramePtr : StackPtr;
1347 X86RegisterInfo::getInitialFrameState(std::vector<MachineMove> &Moves) const {
1348 // Calculate amount of bytes used for return address storing
1349 int stackGrowth = (Is64Bit ? -8 : -4);
1351 // Initial state of the frame pointer is esp+stackGrowth.
1352 MachineLocation Dst(MachineLocation::VirtualFP);
1353 MachineLocation Src(StackPtr, stackGrowth);
1354 Moves.push_back(MachineMove(0, Dst, Src));
1356 // Add return address to move list
1357 MachineLocation CSDst(StackPtr, stackGrowth);
1358 MachineLocation CSSrc(getRARegister());
1359 Moves.push_back(MachineMove(0, CSDst, CSSrc));
1362 unsigned X86RegisterInfo::getEHExceptionRegister() const {
1363 llvm_unreachable("What is the exception register");
1367 unsigned X86RegisterInfo::getEHHandlerRegister() const {
1368 llvm_unreachable("What is the exception handler register");
1373 unsigned getX86SubSuperRegister(unsigned Reg, EVT VT, bool High) {
1374 switch (VT.getSimpleVT().SimpleTy) {
1375 default: return Reg;
1380 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
1382 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
1384 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
1386 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
1392 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
1394 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
1396 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
1398 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
1400 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
1402 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
1404 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
1406 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
1408 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
1410 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
1412 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
1414 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
1416 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
1418 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
1420 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
1422 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
1428 default: return Reg;
1429 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
1431 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
1433 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
1435 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
1437 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
1439 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
1441 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
1443 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
1445 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
1447 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
1449 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
1451 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
1453 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
1455 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
1457 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
1459 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
1464 default: return Reg;
1465 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
1467 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
1469 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
1471 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
1473 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
1475 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
1477 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
1479 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
1481 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
1483 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
1485 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
1487 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
1489 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
1491 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
1493 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
1495 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
1500 default: return Reg;
1501 case X86::AH: case X86::AL: case X86::AX: case X86::EAX: case X86::RAX:
1503 case X86::DH: case X86::DL: case X86::DX: case X86::EDX: case X86::RDX:
1505 case X86::CH: case X86::CL: case X86::CX: case X86::ECX: case X86::RCX:
1507 case X86::BH: case X86::BL: case X86::BX: case X86::EBX: case X86::RBX:
1509 case X86::SIL: case X86::SI: case X86::ESI: case X86::RSI:
1511 case X86::DIL: case X86::DI: case X86::EDI: case X86::RDI:
1513 case X86::BPL: case X86::BP: case X86::EBP: case X86::RBP:
1515 case X86::SPL: case X86::SP: case X86::ESP: case X86::RSP:
1517 case X86::R8B: case X86::R8W: case X86::R8D: case X86::R8:
1519 case X86::R9B: case X86::R9W: case X86::R9D: case X86::R9:
1521 case X86::R10B: case X86::R10W: case X86::R10D: case X86::R10:
1523 case X86::R11B: case X86::R11W: case X86::R11D: case X86::R11:
1525 case X86::R12B: case X86::R12W: case X86::R12D: case X86::R12:
1527 case X86::R13B: case X86::R13W: case X86::R13D: case X86::R13:
1529 case X86::R14B: case X86::R14W: case X86::R14D: case X86::R14:
1531 case X86::R15B: case X86::R15W: case X86::R15D: case X86::R15:
1540 #include "X86GenRegisterInfo.inc"
1543 struct MSAH : public MachineFunctionPass {
1545 MSAH() : MachineFunctionPass(ID) {}
1547 virtual bool runOnMachineFunction(MachineFunction &MF) {
1548 const X86TargetMachine *TM =
1549 static_cast<const X86TargetMachine *>(&MF.getTarget());
1550 const X86RegisterInfo *X86RI = TM->getRegisterInfo();
1551 MachineRegisterInfo &RI = MF.getRegInfo();
1552 X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
1553 unsigned StackAlignment = X86RI->getStackAlignment();
1555 // Be over-conservative: scan over all vreg defs and find whether vector
1556 // registers are used. If yes, there is a possibility that vector register
1557 // will be spilled and thus require dynamic stack realignment.
1558 for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
1559 RegNum < RI.getLastVirtReg(); ++RegNum)
1560 if (RI.getRegClass(RegNum)->getAlignment() > StackAlignment) {
1561 FuncInfo->setReserveFP(true);
1569 virtual const char *getPassName() const {
1570 return "X86 Maximal Stack Alignment Check";
1573 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1574 AU.setPreservesCFG();
1575 MachineFunctionPass::getAnalysisUsage(AU);
1583 llvm::createX86MaxStackAlignmentHeuristicPass() { return new MSAH(); }